1. Field of the Invention
The present invention relates to a method and system for inspecting an assembly consisting of a plurality of parts, especially for inspecting a flash unit. More particularly, the present invention relates to a method and apparatus for inspecting electrical properties of a flash unit of a recovered lens-fitted photographic film package as to if the flash unit is reusable.
2. Related Art
Lens-fitted photographic film packages (hereinafter referred to simply as film packages) are now on the market. As disclosed in U.S. Pat. No. 4,884,087, the film packages are preloaded with a 135-type photographic film cassette (hereinafter referred to as film cassette) defined by the International Standard Organization (ISO) version 1007, 1979. A package housing of the film package is constitute of a main section loaded with the film cassette, a front cover secured in front of the main section, and a rear cover secured behind the main section. The main section includes a shutter mechanism and a taking lens. The film package is intended to be forwarded to a photo-lab in its entirety after photography. In the photo-lab, a photofinisher removes the cassette with the exposed photo film, treats the photo film in development and printing while using a conventional photofinishing system, to produce photo-prints. The photo-prints and the developed photo film are returned to the user.
Also a film package with a built-in flash device is disclosed, e.g. in U.S. Pat. No. 5,315,484.
Meanwhile, in the interest of environmental protection or the reduction of industrial waste, public concern is now directed to recycling parts of industrial products. Also the used film packages are recovered from the photofinishers, and disassembled and inspected by the manufacturer or the like, and reused in new film packages or melted for use as raw materials. To this end, film packages suitable for reuse have recently been proposed. For example, in the film package disclosed in U.S. Pat. No. 5,315,484, exposure mechanisms including a shutter, film advancing and frame counting mechanisms are assembled into a shutter unit which may also be referred to as a photo-taking unit. Also a flash device is formed as an independent assembly having a flash tube, a main capacitor and other electric components or parts mounted on a printed circuit board, so as to be reusable in a new film package.
In order to reuse an assembly, the assembly must be inspected as to if the assembly operates normally. Also the flash unit and the photo-taking unit of the film package must be inspected regarding their performance before reuse. However, most of the process of the conventional inspection has not yet been automated, and the photo-taking unit and the flash unit have so many members to be inspected, that the conventional manual inspection has been very complicated and time-consuming. Particularly, the flash unit must be inspected regarding more than twenty items, including appearance of the flash emitting portion and electrical performance of the flash tube.
In addition, for measuring electrical properties of the flash unit, it is necessary to repeat charging and discharging the main capacitor many times, and that, charging of the main capacitor takes relatively large time in the conventional inspection process. This also increases the total time necessary for inspecting a flash unit. Consequently, recycling the flash unit has been uneconomical.
Furthermore, while the data obtained by the inspection is conventionally utilized merely for judging whether the inspected assembly is reusable or not, it is desirable to make use of the inspection data for other purpose, e.g., for grasping the failure occurrence in the assemblies after marketing.